Crankshaft grinding apparatus



Nov. 29, 1938. A. J. SIEV ERS, JR ,1

v CRANKSHAFT GRINDING APPARATUS File d Feb. 6, 1937 @fife erj BY 0 1 ATTORNEY.

. INVENTOR. ///er/ J.

CRANKSHAFT GRINDING APPARATUS Filed Feb. 6, 1937 3 Sheets-Sheet 2 i l 6 75 Egg /7 3 5 79 77 u IHHHIHH H I INVENTOR.

- X1 F'1E 4= BY ggay zf ATTORNEY.

Nov. 29, 1938. A. .1. SIEVERS. JR

CRANKSHAFT GRINDING APPARATUS 4/ber/ J 17 Filed Feb. 6, 1937 Patented Nov. 29, 1938 or the like. Th

Albert FFICE- 2,138,258 caaivxsum GRINDING srrmrus J.- Sievers,

Calif and one-third d, Calif.

Oakland, calm, assignmof one-third to Edward W. Oliver,

to Phelps E.

Piedmont, Gooch, Oak- Application February 6, 1937, Serial No. 124,400

forms a continuation, in part, of

application Serial Number 75,514, filed April 21, 1936.

20 to grinding of the crank shaft.

llclaims.

e presentapplication my co-pending The invention possesses other objects and fea- 30 as set forth in the claims.

Referring to said drawings:

Figure 1 is a side elevatio line li of Figure 2 is a Figure 3.

side elevation ratus illustrated in Figure 1.

Figure 3 is the apparatus.

Figure through part tially on the Figure 5 is shaft.

Figure 6 is a cross illustrated in Figure on the plane of line Figure 7 is a cross illustrated in Figure on the plane 01' line 4 is a longitudinal s of the base s plane of line 4 a front eleva grinding apparatus which is n of an apparatus conof part of the appaa plan view of the base support 01' ectional view taken upport and substan- 4 of Figure 3.

tion of a part 01 the attached to the crank -sectional view of the device 5 and is taken substantially 5 B6 of Figur -sectional view of the device 5 and is taken substantially l- 7 of Figur Figure 8 is a fragmentary front elevational view on a smaller scale showing a modified form of the invention.

Figure 9 is a cross-sectional view taken along the line 99 of Figure 8.

The apparatus of the present invention, as hereinabove mentioned,

the axis of the crank in my co-pending application, Serial Number 33 which are advanceable in a radial inward direction to engage the periphery of the crank pin or 'other cylindrical surface to be ground. Preferably, each/of the members 33 are formed at their inner face to receive a plurality of abrasive stones or elements 39 which serve on rotation of the assembly to grind the periphery of the surface with which they are engaged.

As an important feature of the invention, the holders 38 of the abrasive members are advanced jointly and simultaneously so that at all times the abrasive stones will be held at substantially equal radii from the axis of the crank pin. This uniform movement of the elements is provided for in the present embodiment by'the engagement of pins 4| on the members 33 in a plurality of spiral grooves 42 in the section 3| so that on relative circumferential displacement of the sec-' tion 32 relative to the section 3| the members 38 will be uniformly radially displaced by the grooves 42. This relative circumferential displacement of the sections may be initially effected by the use of a key 43 which may be inserted into an opening 44 in the section 32 and is formed at its inner end with a pinion 45 which is engageable with a plurality of gear teeth 41 formed over a portion of the inside circumferential face 35 of the section 3|.

In accordance with the present invention the abrasive members after initial setting by the key as above explained, may be moved inwardly against the surface being ground during rotation of the assembly around the surface so that the surface may be speedily brought into proper roundness without stopping the rotation of the device for readjustment of the abrasive. members. This inward movement of the abrasive members against the work during the grinding of the work is effected in the present embodiment by two assisting constructions. One feature of this arrangement is the utilization of the frictional drag of the abrasive elements on the work, to assist in the inward movement of the grinding members. As will be seen from the drawings, the rotation of the means 24 is effected by applying a rotative force directly to the section 3| such as by means of a belt 43 which engages in a circumferential belt groove 49 in the section 3| and is driven. from one of the drive pulleys IS. The means 24 is so postloned around the surface to be ground and with respect to the direction of rotation, that the direction of rotation of the means will be in the direction of a radial outward extension of the spiral grooves 42. Thus, the frictional drag on the abrasive elements against the surface will tend to cause the section 32 to lag behind the section 3| and accordingly set up a circumferential force differential between the sections which force acts through the spiral grooves 42 and the pins 4| to urge the abrasive members inwardly during rotation. In many instances, due to the character of the surface being ground and the relative hardness and consistency ofthe abrasive: used the inward force of the abrasive elements against the work caused by the force differential between the sections, as above explained, may be considerably smaller than that which may be used for efliciently grinding the surface. I have therefore, and in accordance with the second construction above mentioned, mounted on the section 32 at the exposed radial side 50 thereof, a plurality of circumferentially spaced outwardly extending projections 5| which may be struck during rotation of the sections to cause a relative circumferenflat spring 58 tial movement of the sections. Usually this striking action is effected by merely positioning a relatively heavy implement or tool against the side 50 of the section 32, so that during rotation, the projections 5| will strike against the implement so positioned. If desired, and as will be understood, the proiectlons 5| may be replaced by notches, recesses or some other form of irregular surface.

In order that any variant in the rotative force applied to the section 3|, such ascaused by any non-uniformity in the out-put of the driving mechanism or by vibration or' the like shall not be translated into a .corresponding variation in the force of the abrasive members against the surface being ground, a check mechanism is preferably employed to prevent a retraction of of a ball clutch consisting of a ball 52 which is carried in a recess 53 atthe periphery of the section 32 and is moved by centrifugal force on rotation of the sections into engagement'with the inner opposite periphery 35 of the sec on 3| so that while permitting relative displacement of the sections in a direction tending to increase the pressure of the abrasive members against the surface to be ground, will wedge against and prevent movement of the periphery 35'upon a relative movement of the sections in an opposite direction. On stopping of the rotation the ball will drop to the base of the recess and away from the side 35 to permit a free relative displacement of the sections.

A slightly modified form of the grinding means 24' is illustrated in Figures 8 and 9 wherein the circumferential force differential between the sections during rotation for moving the abrasive elements against the work is established, at least in part, by the resilient spring mechanism. As will be seen from these figures, the toothed peripheral portion 41' of the section 3| is engaged by a pinion 45 carried directly in the body of the section 32. The pinion is provided with a wrench opening 55 for turning of the pinion and for adjustment of the sections and such turning may be effected by an ordinary wrench or by a spring press key 53 here illustrated. This key is provided with a shank 51 which is engageable in the wrench opening 55 and is provided with a transversely extending which may be flexed to behind a stop 50 for urging the rotation of the key and pinion.

Preferably the abrasive elements 39 are of a considerable width and may extend axially for a greater length than the combined axial width of the sections 3| and 32 but are preferably somewhat shorter than the be ground so that at least a small reciprocation of the abrasive elements lengthwise over the surface during rotation is permitted. This lengthwise movement of the abrasive members not only insures a more perfect finish but also assists in preventing the abrasive elements from clogging up and becoming partially ineffectual and also likely scoring the surface being ground. The holders 38 for the abrasive members are preferably formed adjacent each of their inner opposite circumferential spaced ends with 'a'trough 40 for catching the loss abrasive and preventing the same from escaping into the inner parts of the mechanism.

Due to the pressure of the drive belt 43 tending to draw the 'rotatable grinding means 24 downlength of the surface to prevent an uneven the means against the tension of the belt 62 surrounds the section an end 63 of the section 48. The spring 8| and abuts against 59 -while the opposite 61 carried by the arm l9. Preferably, and as will be seen in Figures 1 and 4, the pin 61 is adjustably carried by the arm l9 and may be fixed in adjusted position as by as various distances above the b and without requiring a change in length of the screw for cutting various radii of curvature oi the inner faces 01' the abrasive elements.

I claim:

1. A crank shaft grinding apparatus for automobiles and the like comprising, a base support an automobile and power driven rosecond means.

2. An apparatus for pin bearings of an automobile or the like withsaid pin bearing.

3. An apparatus for grinding crank shaft pin bearings comprising,

of said 4. An apparatus for grinding crank shaft pin bearings and the like comprising, a. support, power support and adapted for positioning of the axis of rotation thereof substantially parallel to the means connecting axis of said shaft, means adapted for assembly around a crank pin bearing of said shaft and provided with an abrasive element effective to grind said bearing on rotation of said means, drive said first and second named means, and a member mounted on said support and supporting said grinder means in substantially concentric relation around said pin bearing and comprising, a pair of slidably attached telescopic sections, a spring connecting said sections and resiliently urging the same to an extended position, and means adjustably positioned on one of said sections and engageable with said spring for controlling the expansible force of said spring against said sections.

6. An apparatus for grinding crank pin bearings of a crank shaft or the like without removing the shaft from its engine mounting comprising, a base support adapted for mounting in spaced relation to said shaft, power driven rotatable means carried by said support and arranged for positioning of the axis of rotation thereof substantially parallel to said shaft, rotatable grinder means adapted for assembly around a pin bearing of'said shaft, drive means connecting said first and second means, an arm on said support providing a bearing portion intermediate said first and second means, said bearing portion having an axis substantially parallel to the axes of said first and second means, and a member provided with a forked end engageable with said arm hearleg portion and engageable with said rotatable grinder means for supporting the latter in substantially concentric relation around said pin bearing and being adapted for fulcrumlng on said arm bearing portion at right angles to its axis to displace said grinder means longitudinally on said pin bearing.

7. An apparatus for grinding crank pin bearings of a crank shaft or the like without removing the shaft from its engine mounting comprising, a base support adapted for mounting in spaced relation to said shaft, power driven rotatable means carried by said support and arranged for positioning of the axis of rotation thereof sub stantially parallel to said, shaft, rotatable grinder means adapted for assembly around a pin bearing of said shaft, drive means connecting said first and second means, an arm on said support intermediate said first and second means and radially extending from said first means and adjustable about the axis thereof, and means supported on said arm and engageable with said second named means for supporting the latter in concentric relation around said crank pin bearing.

8. An apparatus for grinding the crank pin bearings of a crank shaft or the like comprising,

a base support arranged for positioning opposite to and spaced from said crank shaft, a plurality of concentric drive pulleys carried by said support, a rotatable grinding means adapted for assembly around a crank pin bearing, belt means for driving said grinding means from saidpulleys, an arm carried by said support and radially extending from the axis of said pulleys and having a portion overlying said pulleys, and means mounted on said portion and engageable with said grinding means for supporting the latter in substantially concentric relation around said pin. said portion being adjustable relative to said arm for positioning opposite to each of said pulleys.

9. A crank shaft grinding apparatus for automobiles and the like comprising, a base support adapted for positioning under an automobile and under the crank shaft thereof, power driven rotatable means carried by said support with the axis of rotation thereof adapted forpositioning substantially parallel to the axis of rotation of said shaft, means for adjusting the plane of said support for positioning the same substantially parallel to said shaft, rotatable grinder means arranged for assembly around one of the crank shaft bearings, means supporting said grinder means from said base support in concentric relation around said bearing, and drive means connecting said first means and said grinder means.

10. A device for grinding cylindrical surfaces or the like comprising, a ring member adapted for mounting around said surface, a plurality of members carried by said ring member and movable radially thereto for engagement with said surface, means eifective to move said members jointly and equally in a radial direction relative to said ring member, a spring means for actuating said last named means.

11. A device for grinding cylindrical surfaces or the like comprising, a ring member adapted for mounting around said surfaces and having sections movable relative to each other circumferentially, a plurality of members carried by said ring member and being movable radially with respect thereto for engagement with said surface, means actuated by a circumferential force differential between said sections to urge said second named members radially inwardly with respect to said ring member, a gear portion on one section, a pinion carried by the other section and engageable with said gear portion, and spring means connected to said pinion and urging rotation of the latter and establishing the aforesaid force differential.

ALBERT J. SIEVERS. Jl. 

